Demolition and Blasting Charges

A demolition charge is a high explosive used for destructive purposes—in bombs, mines, shells, missiles, and torpedoes. A blasting charge is a high explosive used for such purposes as mining and building roads. Demolition and blasting charges include:

TNT

(trinitrotoluene), the most important military chemical explosive. It is a pale yellow crystalline substance that can be safely melted and cast into charges for artillery shells and bombs. TNT is often combined with other explosives. It is made by treating toluene (a chemical obtained from the refining of petroleum or coal tar) with a mixture of nitric and sulfuric acids.

Nitroglycerin

a yellow, oily liquid produced by mixing glycerol with nitric and sulfuric acids. It is a very powerful explosive and very sensitive to shock, making it dangerous to handle. It is almost always combined with more stable materials.

Dynamite

an explosive made by combining nitro-glycerin with an absorbent material (such as wood pulp) and other ingredients (such as ammonium nitrate or sodium nitrate). Dynamite is relatively safe to handle and was long the most important explosive for blasting. It has been largely replaced by less expensive and less sensitive materials composed primarily of ammonium nitrate.

Ammonium Nitrate

a colorless crystalline substance made by treating nitric acid with ammonia vapor. It does not readily explode, but in combination with fuels and more sensitive explosives (such as TNT) it is very effective in blasting operations. ANFO, a mixture typically consisting of 94 per cent ammonium nitrate and 6 per cent fuel oil, is a relatively inexpensive material widely used for blasting. Slurry, or water gel, explosives consist essentially of thickened solutions of ammonium nitrate. They have a high resistance to water and are suitable for use in wet conditions. Slurries typically contain a number of ingredients, including sodium nitrate, calcium nitrate, aluminum, ethylene glycol, and TNT, whose proportions depend on the explosive characteristics desired. Amatol is a mixture of roughly equal amounts of TNT and ammonium nitrate.

Picric Acid

(trinitrophenol), a yellow crystalline solid made by heating phenol with concentrated sulfuric acid and then treating the mixture with nitric acid. Picric acid is the chief component of the British explosive lyddite. Picric acid was an important military explosive in World War I.

Ammonium Picrate, or Explosive D

a powerful high explosive. It is produced through the action of picric acid upon ammonia. It is extremely insensitive to shock or friction, making it suitable for armor-piercing shells (shells that penetrate armor plate and explode inside a warship or tank by means of a delayed fuze).

Permissible Explosives

special high explosives used for blasting in underground coal mines. They typically contain ammonium nitrate and nitroglycerin and are formulated to explode at a relatively low temperature, so that that will not ignite mine gases or coal dust.